Synergies between electronic and geometric effects of Mo-doped Au nanoparticles for effective CO2 electrochemical reduction

Abstract

CO₂ electroreduction is developing as a promising technology to solve environmental and energy problems. Alloy catalysts with dissimilar local metal atoms induce geometric and electronic effects that may greatly contribute to their performance. However, the fundamental mechanisms for CO₂ reduction on a bimetallic Au alloy surface are still ambiguous. Here, we report effective CO₂ reduction by the synergies between electronic and geometric effects of Mo-doped Au nanoparticles (MDA NPs). A 97.5% CO faradaic efficiency and 75-fold higher current density than pure Au nanoparticles were achieved at −0.4 V versus the reversible hydrogen electrode for MDA NPs with at least 50 h lifetime. Our experimental and theoretical calculation results reveal that the Au surface with increased electron density from Mo can effectively enhance CO₂ activation. Moreover, the intermediate *COOH may be further stabilized by the local Mo atom through additional Mo–O binding to decrease the energy barrier.